swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: f40ddce88593482919761f74910f42f4b84c004b authored by Linus Torvalds on 14 February 2021, 22:32:24 UTC
Linux 5.11
Linux 5.11
Tip revision: f40ddce
timer_int.c
/**
* @file timer_int.c
*
* @remark Copyright 2002 OProfile authors
* @remark Read the file COPYING
*
* @author John Levon <levon@movementarian.org>
*/
#include <linux/kernel.h>
#include <linux/notifier.h>
#include <linux/smp.h>
#include <linux/oprofile.h>
#include <linux/profile.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/hrtimer.h>
#include <asm/irq_regs.h>
#include <asm/ptrace.h>
#include "oprof.h"
static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer);
static int ctr_running;
static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer)
{
oprofile_add_sample(get_irq_regs(), 0);
hrtimer_forward_now(hrtimer, ns_to_ktime(TICK_NSEC));
return HRTIMER_RESTART;
}
static void __oprofile_hrtimer_start(void *unused)
{
struct hrtimer *hrtimer = this_cpu_ptr(&oprofile_hrtimer);
if (!ctr_running)
return;
hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer->function = oprofile_hrtimer_notify;
hrtimer_start(hrtimer, ns_to_ktime(TICK_NSEC),
HRTIMER_MODE_REL_PINNED);
}
static int oprofile_hrtimer_start(void)
{
get_online_cpus();
ctr_running = 1;
on_each_cpu(__oprofile_hrtimer_start, NULL, 1);
put_online_cpus();
return 0;
}
static void __oprofile_hrtimer_stop(int cpu)
{
struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu);
if (!ctr_running)
return;
hrtimer_cancel(hrtimer);
}
static void oprofile_hrtimer_stop(void)
{
int cpu;
get_online_cpus();
for_each_online_cpu(cpu)
__oprofile_hrtimer_stop(cpu);
ctr_running = 0;
put_online_cpus();
}
static int oprofile_timer_online(unsigned int cpu)
{
local_irq_disable();
__oprofile_hrtimer_start(NULL);
local_irq_enable();
return 0;
}
static int oprofile_timer_prep_down(unsigned int cpu)
{
__oprofile_hrtimer_stop(cpu);
return 0;
}
static enum cpuhp_state hp_online;
static int oprofile_hrtimer_setup(void)
{
int ret;
ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
"oprofile/timer:online",
oprofile_timer_online,
oprofile_timer_prep_down);
if (ret < 0)
return ret;
hp_online = ret;
return 0;
}
static void oprofile_hrtimer_shutdown(void)
{
cpuhp_remove_state_nocalls(hp_online);
}
int oprofile_timer_init(struct oprofile_operations *ops)
{
ops->create_files = NULL;
ops->setup = oprofile_hrtimer_setup;
ops->shutdown = oprofile_hrtimer_shutdown;
ops->start = oprofile_hrtimer_start;
ops->stop = oprofile_hrtimer_stop;
ops->cpu_type = "timer";
printk(KERN_INFO "oprofile: using timer interrupt.\n");
return 0;
}